The US$274 million third-quarter loss compared with a net profit of $63 million a year earlier. Net sales grew to $13.8 billion from $10.9 billion a year earlier, Amazon said Thursday.

A large chunk of the net loss, $169 million, was related to the company's investment in online deal site LivingSocial, it said. At the same time total operating expenses increased from $10.8 billion to $13.8 billion.

Amazon is now in the process of rolling out its new family of Kindle tablets and e-readers. The Kindle Fire HD, a tablet with a color screen running Android, is Amazon's bestselling product worldwide, followed by the new Kindle Paperwhite e-reader and the $69 Kindle, the company said.

CEO Jeff Bezos has high hopes for the Kindle range, and said the best is yet to come: A version of the Kindle Fire HD with an 8.9-inch screen will go on sale on Nov. 20.

The new Kindles will face stiff competition during the holiday shopping season, thanks to the arrival of the iPad mini and more Nexus tablets from Google. The latter are expected to be announced on Oct. 29.